TL494C, TL494I, TL494M, TL494Y
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
SLVS074A – JANUARY 1983 – REVISED AUGUST 1995
•
•
•
•
•
Complete PWM Power Control Circuitry
TL494C, TL494I . . . D, N, OR PW PACKAGE
TL494M . . . J PACKAGE
(TOP VIEW)
Uncommitted Outputs for 200-mA Sink or
Source Current
Output Control Selects Single-Ended or
Push-Pull Operation
1IN +
1
16
2IN +
1IN –
2
15
2IN –
FEEDBACK
3
14
REF
DTC
4
13
OUTPUT CTRL
CT
5
12
RT
6
11
VCC
C2
GND
7
10
E2
C1
8
9
E1
Internal Circuitry Prohibits Double Pulse at
Either Output
Variable Dead Time Provides Control Over
Total Range
Internal Regulator Provides a Stable 5-V
Reference Supply With 5% Tolerance
TL494M . . . FK PACKAGE
Circuit Architecture Allows Easy
Synchronization
(TOP VIEW)
1IN–
1IN+
NC
2IN+
2IN–
•
•
description
FEEDBACK
DTC
NC
CT
RT
The TL494 contains two error amplifiers, an
on-chip adjustable oscillator, a dead-time control
(DTC) comparator, a pulse-steering control
flip-flop, a 5-V, 5%-precision regulator, and
output-control circuits.
4
3 2 1 20 19
18
5
17
6
16
7
15
8
14
9 10 11 12 13
REF
OUTPUT CTRL
NC
VCC
C2
GND
C1
NC
E1
E2
The TL494 incorporates on a single monolithic
chip all the functions required in the construction
of a pulse-width-modulation control circuit.
Designed primarily for power supply control, this
device offers the systems engineer the flexibility to
tailor the power supply control circuitry to a
specific application.
NC – No internal connection
FUNCTION TABLE
The error amplifiers exhibit a common-mode
voltage range from – 0.3 V to VCC – 2 V. The
dead-time control comparator has a fixed offset
that provides approximately 5% dead time. The
on-chip oscillator may be bypassed by terminating
RT to the reference output and providing a
sawtooth input to CT, or it may drive the common
circuits in synchronous multiple-rail power
supplies.
INPUT TO
OUTPUT
CTRL
OUTPUT FUNCTION
VI = GND
VI = Vref
Single-ended or parallel output
Normal push-pull operation
AVAILABLE OPTIONS
PACKAGED DEVICES
CHIP
FORM
(Y)
TA
SURFACE MOUNT
(D)†
CHIP CARRIER
(FK)
CERAMIC DIP
(J)
PLASTIC DIP
(N)
SHRINK
SMALL OUTLINE
(PW)‡
0°C to 70°C
TL494CD
—
—
TL494CN
TL494CPW
TL494Y
– 40°C to 85°C
TL494ID
—
—
TL494IN
—
—
—
—
– 55°C to 125°C
—
TL494MFK
TL494MJ
—
† The D package is available taped and reeled. Add R suffix to device type (e.g., TL494CDR).
‡ The PW package is only available left-end taped and reeled.
Copyright  1995, Texas Instruments Incorporated
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
On products compliant to MIL-STD-883, Class B, all parameters are
tested unless otherwise noted. On all other products, production
processing does not necessarily include testing of all parameters.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
4–1
TL494C, TL494I, TL494M, TL494Y
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
SLVS074A – JANUARY 1983 – REVISED AUGUST 1995
description (continued)
The uncommitted output transistors provide either common-emitter or emitter-follower output capability. The
TL494 provides for push-pull or single-ended output operation, which may be selected through the outputcontrol function. The architecture of this device prohibits the possibility of either output being pulsed twice during
push-pull operation.
The TL494C is characterized for operation from 0°C to 70°C. The TL494I is characterized for operation from
– 40°C to 85°C. The TL494M is characterized for operation from – 55°C to 125°C.
functional block diagram
OUTPUT CTRL
(see Function Table)
13
6
RT
5
CT
DTC
4
Oscillator
Dead-Time Control
Comparator
≈ 0.1 V
1IN+
1IN–
2
8
9
Q2
PWM
Comparator
11
10
+
12
16
2IN–
15
3
Reference
Regulator
–
0.7 mA
NOTE A. The terminal numbers indicated apply only to the D, J, N, and PW packages.
4–2
C2
E2
VCC
+
14
7
FEEDBACK
E1
Pulse-Steering
Flip-Flop
–
Error Amplifier 2
2IN+
C1
C1
Error Amplifier 1
1
Q1
1D
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
REF
GND
TL494C, TL494I, TL494M, TL494Y
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
SLVS074A – JANUARY 1983 – REVISED AUGUST 1995
TL494Y chip information
This chip, when properly assembled, display characteristics similar to the TL494C. Thermal compression or
ultrasonic bonding may be used on the doped aluminum bonding pads. The chips may be mounted with
conductive epoxy or a gold-silicon preform.
BONDING PAD ASSIGNMENTS
(13)
(14)
(12)
(15)
(11)
(16)
CHIP THICKNESS: 15 MILS TYPICAL
(10)
80
(9)
BONDING PADS: 4 × 4 MILS MINIMUM
TJmax = 150°C
TOLERANCES ARE ± 10%.
ALL DIMENSIONS ARE IN MILS.
(1)
(8)
(2)
(3)
(7)
(6)
(5)
(4)
94
1IN+
1IN –
FEEDBACK
DTC
CT
RT
GND
C1
(1)
(16)
(2)
(15)
(3)
(14)
(4)
(13)
(5)
TL494Y
(12)
(6)
(11)
(7)
(10)
(8)
(9)
POST OFFICE BOX 655303
2IN+
2IN –
REF
OUTPUT CTRL
VCC
C2
E2
E1
• DALLAS, TEXAS 75265
4–3
TL494C, TL494I, TL494M, TL494Y
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
SLVS074A – JANUARY 1983 – REVISED AUGUST 1995
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)†
TL494C
TL494I
TL494M
UNIT
41
41
41
V
VCC + 0.3
41
VCC + 0.3
41
VCC + 0.3
41
V
Collector output voltage, VO
Collector output current, IO
250
250
250
mA
Supply voltage, VCC (see Note 1)
Amplifier input voltage, VI
Continuous total power dissipation
V
See Dissipation Rating Table
0 to 70
– 40 to 85
–55 to 125
°C
– 65 to 150
– 65 to 150
– 65 to 150
°C
—
—
260
°C
260
260
—
°C
Operating free-air temperature range, TA
Storage temperature range, Tstg
Case temperature for 60 seconds, TC: FK package
Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds: D, N, or PW
package
Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds: J package
—
—
300
°C
† Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
NOTE 1: All voltage values, except differential voltages, are with respect to the network ground terminal.
DISSIPATION RATING TABLE
TA ≤ 25°C
POWER RATING
D
900 mW
7.6 mW/°C
DERATE
ABOVE TA
25°C
558 mW
444 mW
—
FK
1375 mW
11.0 mW/°C
25°C
880 mW
715 mW
275 mW
275 mW
PACKAGE
DERATING
FACTOR
TA = 70°C
POWER RATING
TA = 85°C
POWER RATING
TA = 125°C
POWER RATING
J
1375 mW
11.0 mW/°C
25°C
880 mW
715 mW
N
1000 mW
9.2 mW/°C
41°C
733 mW
595 mW
—
PW
700 mW
5.6 mW/°C
25°C
448 mW
—
—
recommended operating conditions
TL494C
MIN
Supply voltage, VCC
Amplifier input voltage, VI
TL494I
MAX
MIN
TL494M
MAX
MIN
MAX
UNIT
7
40
7
40
7
40
V
– 0.3
VCC – 2
40
– 0.3
VCC – 2
40
– 0.3
VCC – 2
40
V
Collector output voltage, VO
V
Collector output current (each transistor)
200
200
200
mA
Current into feedback terminal
0.3
0.3
0.3
mA
kHz
Oscillator frequency, fosc
Timing capacitor, CT
Timing resistor, RT
Operating free-air temperature, TA
4–4
POST OFFICE BOX 655303
1
300
1
300
1
300
0.47
10 000
0.47
10 000
0.47
10 000
nF
1.8
500
1.8
500
1.8
500
kΩ
0
70
– 40
85
– 55
125
°C
• DALLAS, TEXAS 75265
TL494C, TL494I, TL494M, TL494Y
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
SLVS074A – JANUARY 1983 – REVISED AUGUST 1995
electrical characteristics over recommended operating free-air temperature range, VCC = 15 V,
f = 10 kHz (unless otherwise noted)
reference section
Output voltage (REF)
Input regulation
Output regulation
TL494C, TL494I
TEST CONDITIONS†
PARAMETER
IO = 1 mA
VCC = 7 V to 40 V
Output voltage change with temperature
IO = 1 mA to 10 mA
∆TA = MIN to MAX
Short-circuit output current§
REF = 0 V
TL494M
TYP‡
UNIT
MIN
TYP‡
MAX
MIN
4.75
5
5.25
4.75
5
5.25
2
25
2
25
mV
1
15
1
15
mV
2
10
2
30*
mV/V
MAX
– 25
25
V
mA
* On products compliant to MIL-STD-883, Class B, this parameter is not production tested.
† For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.
‡ All typical values except for parameter changes with temperature are at TA = 25°C.
§ Duration of the short circuit should not exceed one second.
oscillator section, CT = 0.01 µF, RT = 12 kΩ (see Figure 1)
TL494C, TL494I
TEST CONDITIONS†
PARAMETER
MIN
TYP‡
Frequency
Standard deviation of frequency¶
All values of VCC, CT, RT, and TA constant
Frequency change with voltage
VCC = 7 V to 40 V,
∆TA = MIN to MAX
Frequency change with temperature#
TA = 25°C
MAX
TL494M
MIN TYP‡
MAX
UNIT
10
10
kHz
100
100
Hz/kHz
1
Hz/kHz
1
10
* On products compliant to MIL-STD-883, Class B, this parameter is not production tested.
Ǹ
† For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.
‡ All typical values except for parameter changes with temperature are at TA = 25°C.
¶ Standard deviation is a measure of the statistical distribution about the mean as derived from the formula:
# Temperature coefficient of timing capacitor and timing resistor not taken into account.
s
+
10*
ȍ
n
Hz/kHz
* X)
+
N*1
N
(x n
2
1
error amplifier section (see Figure 2)
PARAMETER
TEST CONDITIONS
TL494C, TL494I
TL494M
MIN
Input offset voltage
Input offset current
VO (FEEDBACK) = 2.5 V
VO (FEEDBACK) = 2.5 V
Input bias current
VO (FEEDBACK) = 2.5 V
VCC = 7 V to 40 V
Open-loop voltage amplification
∆VO = 3 V,
RL = 2 kΩ,
VO = 0.5 V to 3.5 V,
VO = 0.5 V to 3.5 V
RL = 2 kΩ
70
UNIT
MAX
2
10
mV
25
250
nA
0.2
1
µA
– 0.3 to
VCC – 2
Common-mode input voltage range
Unity-gain bandwidth
TYP‡
V
95
dB
800
kHz
65
80
dB
V (FEEDBACK) = 0.7 V
0.3
0.7
mA
Output source current (FEEDBACK)
VID = 15 mV to 5 V,
V (FEEDBACK) = 3.5 V
‡ All typical values except for parameter changes with temperature are at TA = 25°C.
–2
Common-mode rejection ratio
Output sink current (FEEDBACK)
∆VO = 40 V,
TA = 25°C
VID = – 15 mV to – 5 V,
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
mA
4–5
TL494C, TL494I, TL494M, TL494Y
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
SLVS074A – JANUARY 1983 – REVISED AUGUST 1995
electrical characteristics over recommended operating free-air temperature range, VCC = 15 V,
f = 10 kHz, TA = 25°C (unless otherwise noted)
reference section
TL494Y
TEST CONDITIONS
PARAMETER
Output voltage (REF)
MIN
TYP†
UNIT
MAX
IO = 1 mA
VCC = 7 V to 40 V
5
V
Input regulation
2
mV
Output regulation
IO = 1 mA to 10 mA
1
mV
Short-circuit output current‡
REF = 0 V
25
mA
oscillator section, CT = 0.01 µF, RT = 12 kΩ (see Figure 1)
TL494Y
TEST CONDITIONS
PARAMETER
MIN
TYP†
Frequency
Standard deviation of frequency§
All values of VCC, CT, RT, and TA constant
Frequency change with voltage
VCC = 7 V to 40 V,
UNIT
MAX
10
kHz
100
Hz/kHz
1
Hz/kHz
TA = 25°C
error amplifier section (see Figure 2)
TL494Y
PARAMETER
Input offset voltage
Input offset current
Input bias current
Open-loop voltage amplification
Unity-gain bandwidth
Common-mode rejection ratio
TEST CONDITIONS
MIN
VO (FEEDBACK) = 2.5 V
VO (FEEDBACK) = 2.5 V
VO (FEEDBACK) = 2.5 V
∆VO = 3 V,
RL = 2 kΩ,
VO = 0.5 V to 3.5 V,
∆VO = 40 V,
TA = 25°C
VO = 0.5 V to 3.5 V
RL = 2 kΩ
Output sink current (FEEDBACK)
VID = – 15 mV to – 5 V,
V (FEEDBACK) = 0.7 V
† All typical values except for parameter changes with temperature are at TA = 25°C.
‡ Duration of the short circuit should not exceed one second.
§ Standard deviation is a measure of the statistical distribution about the mean as derived from the formula:
s
4–6
TYP†
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
+
MAX
UNIT
2
mV
25
nA
0.2
µA
95
dB
800
kHz
Ǹ
80
dB
ȍ
mA
n
0.7
N
+1
* X)
N*1
(x n
2
TL494C, TL494I, TL494M, TL494Y
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
SLVS074A – JANUARY 1983 – REVISED AUGUST 1995
electrical characteristics over recommended operating free-air temperature range, VCC = 15 V,
f = 10 kHz (unless otherwise noted)
output section
PARAMETER
TL494C, TL494I
TL494M, TL494Y
TEST CONDITIONS
MIN
Collector off-state current
Emitter off-state current
Collector-emitter saturation voltage
Common emitter
Emitter follower
VCE = 40 V,
VCC = VC = 40 V,
VCC = 40 V
VE = 0
VE = 0,
VO(C1 or C2) = 15 V,
IC = 200 mA
IE = – 200 mA
TYP†
2
UNIT
MAX
100
µA
– 100
µA
1.1
1.3
1.5
2.5
Output control input current
VI = Vref
† All typical values except for temperature coefficient are at TA = 25°C.
3.5
V
mA
dead-time control section (see Figure 1)
PARAMETER
TEST CONDITIONS
TL494C, TL494I
TL494Y
MIN
Input bias current (DEAD-TIME CTRL)
Maximum duty cycle, each output
VI = 0 to 5.25 V
VI (DEAD-TIME CTRL) = 0,
CT = 0.1 µF, RT = 12 kΩ
TYP†
MAX
–2
– 10
3
Maximum duty cycle
MIN
45%
Zero duty cycle
Input threshold voltage (DEAD-TIME
(DEAD TIME CTRL)
TL494M
3.3
UNIT
TYP†
MAX
–2
– 10
45%
50%*
3
3.3
V
0*
0
µA
* On products compliant to MIL-STD-883, Class B, this parameter is not production tested.
† All typical values except for temperature coefficient are at TA = 25°C.
PWM comparator section (see Figure 1)
PARAMETER
TL494C, TL494I
TL494M, TL494Y
TEST CONDITIONS
Input threshold voltage (FEEDBACK)
Zero duty cycle
Input sink current (FEEDBACK)
V (FEEDBACK) = 0.7 V
UNIT
MIN
TYP†
MAX
4
4.5
0.3
0.7
V
mA
† All typical values except for temperature coefficient are at TA = 25°C.
total device
PARAMETER
TL494C, TL494I
TL494Y
TEST CONDITIONS
MIN
Standby supply current
RT = Vref,
All other inputs and outputs open
MAX
10
6
21
15
9
26
MAX
6
9
Average supply current
VI (DEAD-TIME CTRL) = 2 V,
See Figure 1
† All typical values except for temperature coefficient are at TA = 25°C.
• DALLAS, TEXAS 75265
7.5
UNIT
TYP†
TYP†
VCC = 15 V
VCC = 40 V
POST OFFICE BOX 655303
TL494M
MIN
7.5
mA
mA
4–7
TL494C, TL494I, TL494M, TL494Y
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
SLVS074A – JANUARY 1983 – REVISED AUGUST 1995
electrical characteristics over recommended operating free-air temperature range, VCC = 15 V,
f = 10 kHz (unless otherwise noted) (continued)
switching characteristics, TA = 25°C
PARAMETER
Rise time
Fall time
Rise time
Fall time
TL494C, TL494I
TL494Y
MIN TYP†
MAX
TEST CONDITIONS
Common-emitter configuration
configuration,
Emitter-follower configuration,
configuration
See Figure 3
See Figure 4
* On products compliant to MIL-STD-883, Class B, this parameter is not production tested.
† All typical values except for temperature coefficient are at TA = 25°C.
4–8
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TL494M
MIN
UNIT
TYP†
MAX
100
200
100
200*
ns
25
100
25
100*
ns
100
200
100
200*
ns
40
100
40
100*
ns
TL494C, TL494I, TL494M, TL494Y
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
SLVS074A – JANUARY 1983 – REVISED AUGUST 1995
PARAMETER MEASUREMENT INFORMATION
VCC = 15 V
150 Ω
2W
12
VCC
4
Test
Inputs
3
12 kΩ
6
5
FEEDBACK
E1
RT
C2
CT
0.01 µF
1
8
C1
DTC
150 Ω
2W
Output 1
9
11
Output 2
10
E2
1IN +
2
16
15
13
1IN –
2IN +
Error
Amplifiers
2IN –
OUTPUT
CTRL
14
REF
GND
50 kΩ
7
TEST CIRCUIT
VCC
Voltage
at C1
0V
VCC
Voltage
at C2
0V
Voltage
at CT
Threshold Voltage
DTC
0V
Threshold Voltage
FEEDBACK
0.7 V
Duty Cycle
MAX
0%
0%
VOLTAGE WAVEFORMS
Figure 1. Operational Test Circuit and Waveforms
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
4–9
TL494C, TL494I, TL494M, TL494Y
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
SLVS074A – JANUARY 1983 – REVISED AUGUST 1995
PARAMETER MEASUREMENT INFORMATION
Amplifier Under Test
+
VI
FEEDBACK
–
+
Vref
–
Other Amplifier
Figure 2. Amplifier Characteristics
15 V
Each Output
Circuit
68 Ω
2W
tf
Output
tr
90%
90%
CL = 15 pF
(See Note A)
TEST CIRCUIT
NOTE A. CL includes probe and jig capacitance.
10%
10%
OUTPUT VOLTAGE WAVEFORM
Figure 3. Common-Emitter Configuration
15 V
Each Output
Circuit
Output
CL = 15 pF
(See Note A)
90%
90%
10%
10%
68 Ω
2W
tr
OUTPUT VOLTAGE WAVEFORM
TEST CIRCUIT
NOTE A. CL includes probe and jig capacitance.
Figure 4. Emitter-Follower Configuration
4–10
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
tf
TL494C, TL494I, TL494M, TL494Y
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
SLVS074A – JANUARY 1983 – REVISED AUGUST 1995
TYPICAL CHARACTERISTICS
f – Oscillator Frequency and Frequency Variation – Hz
OSCILLATOR FREQUENCY AND
FREQUENCY VARIATION†
vs
TIMING RESISTANCE
100 k
VCC = 15 V
TA = 25°C
40 k
– 2%
0.001 µF
–1%
10 k
0.01 µF
0%
4k
0.1 µF
1k
400
†
∆f = 1%
100
CT = 1 µF
40
10
1k
4k
10 k
40 k 100 k
RT – Timing Resistance – Ω
400 k
1M
Figure 5
† Frequency variation (∆f) is the change in oscillator frequency that occurs over the full temperature range.
AMPLIFIER VOLTAGE AMPLIFICATION
vs
FREQUENCY
A – Amplifier Voltage Amplification – dB
100
VCC = 15 V
∆VO = 3 V
TA = 25°C
90
80
70
60
50
40
30
20
10
0
1
10
100
1k
10 k
100 k
1M
f – Frequency – Hz
Figure 6
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
4–11
4–12
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
IMPORTANT NOTICE
Texas Instruments (TI) reserves the right to make changes to its products or to discontinue any semiconductor
product or service without notice, and advises its customers to obtain the latest version of relevant information
to verify, before placing orders, that the information being relied on is current.
TI warrants performance of its semiconductor products and related software to the specifications applicable at
the time of sale in accordance with TI’s standard warranty. Testing and other quality control techniques are
utilized to the extent TI deems necessary to support this warranty. Specific testing of all parameters of each
device is not necessarily performed, except those mandated by government requirements.
Certain applications using semiconductor products may involve potential risks of death, personal injury, or
severe property or environmental damage (“Critical Applications”).
TI SEMICONDUCTOR PRODUCTS ARE NOT DESIGNED, INTENDED, AUTHORIZED, OR WARRANTED
TO BE SUITABLE FOR USE IN LIFE-SUPPORT APPLICATIONS, DEVICES OR SYSTEMS OR OTHER
CRITICAL APPLICATIONS.
Inclusion of TI products in such applications is understood to be fully at the risk of the customer. Use of TI
products in such applications requires the written approval of an appropriate TI officer. Questions concerning
potential risk applications should be directed to TI through a local SC sales office.
In order to minimize risks associated with the customer’s applications, adequate design and operating
safeguards should be provided by the customer to minimize inherent or procedural hazards.
TI assumes no liability for applications assistance, customer product design, software performance, or
infringement of patents or services described herein. Nor does TI warrant or represent that any license, either
express or implied, is granted under any patent right, copyright, mask work right, or other intellectual property
right of TI covering or relating to any combination, machine, or process in which such semiconductor products
or services might be or are used.
Copyright  1995, Texas Instruments Incorporated